Biomagnification of organohalogens in Atlantic salmon (Salmo salar) from its main prey species in three areas of the Baltic Sea

Factors affecting the biomagnification of organohalogens in Baltic salmon from sprat, herring and three-spined stickleback were assessed in three feeding areas. Second sea-year salmon contained (in fresh weight of whole fish) 79–250 ng g− 1 polychlorinated biphenyls (ΣPCB), 0.9–2.7 pg g− 1 dibenzo-p-dioxins (ΣPCDD), 8–19 pg g− 1 dibenzofurans (ΣPCDF), 96–246 pg g− 1 coplanar PCBs, 2.4–3.6 ng g− 1 polybrominated diphenylethers (ΣPBDE), and 39–136 ng g− 1 Σindicator PCB6. The EU limits for WHO toxic equivalent concentrations in fish feed were already exceeded in one-year-old sprat and herring and were exceeded many-fold in older age groups. The differences in the biomagnification rates of organohalogens in salmon appeared to be related to the feeding area, principal prey species, and the fat content and growth rate of the prey species.

► Biomagnification of organohalogens in Baltic salmon from prey fish was studied.
► Biomagnification rate was related to area and prey species and their quality.
► Accumulation rate of organohalogens with age was fastest in salmon.
► The WHO-TEQs for animal feed were exceeded already in 1-year-old sprat and herring.
► Ratio of 2,3,4,7,8-PeCDF to 2,3,7,8-TCDF increased with age of fish.